Liquid composite moulding for processes such as resin transfer moulding hold great industrial interest for manufactures of complex thick composite structures. At present, one significant drawback to the widespread introduction of such structures into advanced engineering applications is the low toughness of the resin system suited to these processes. This disadvantage is particularly acute in the domain of civil aerospace where the material properties of composites are extremely demanding.
The low viscosity required for liquid composite moulding precludes the use of thermoplastic toughening agents. This results in composite structures with a low toughness, and therefore limited damage tolerant performance.
One solution to this problem is the augmentation of conventional composite structures with carbon nanotubes (CNTs). It has been demonstrated in the literature that secondary carbon nanotubes can be grown on the surfaces of primary carbon fibres.
If the carbon nanotubes can be grown with an appropriate concentration relative to each other, self-alignment can be obtained as a result of the van der Waals interactions between the tubes.
Thus an aligned CNT structure can be formed between the fibres. However, no process currently exists for the practical fabrication of composite components exhibiting such a structure.